Another spring, another sputtering American recovery. For the third year in a row, what many anticipated to be a return to robust growth is beginning to look like another summer of hibernation. Last Friday’s payroll numbers showed a 115,000 drop in joblessness, barely enough to match population growth. And the ratio of Americans seeking work continues to go in the wrong direction, which flatters the official unemployment number. It fell a decimal point to 8.1 per cent last month. If no one had dropped out of the labour market, the official rate would have risen.

None of this should be much of a surprise. There are plenty of external factors to blame – the crisis in the eurozone, the persistence of relatively high global oil prices and expectations of a slowdown in China and India. To a greater extent than before, the US economy is affected by what happens to demand elsewhere. US domestic spending power is no longer the prime mover in today’s global economy. That era is unlikely to return.

These are structural forces that have been steadily deepening. With each business cycle in the past 20 years, it has taken longer to return to growth and to restore full employment than before. In each case the market clears at a lower price than in the previous expansion. The US is about to enter its fourth year of recovery. The median household income is considerably lower than it was in June 2009, when the recovery began. It is likely to be lower still in November when Barack Obama faces re-election.